Geodetic reference systems may be used by the Global Positioning System. Accordingly, mapping data according to a geodetic system may be very useful in a variety of applications. For example, systems using the North American Datum, e.g., the North American Datum of 1927 (NAD27) or the North American Datum of 1983 (NAD83), are geodetic systems. Similarly, the World Geodetic System, which presently uses data according to the WGS 84 and serves as the reference system for the Global Positioning System, is a geodetic system. In a geodetic system, a location is provided with respect to a reference ellipsoid according to latitude, longitude, and height coordinates.
Mapping data may be provided in other formats, e.g., Cartesian formats such as the Universal Transverse Mercator (UTM) or State Plane Coordinate System (SPC or SPCS). In these Cartesian formats, the surface of the earth is divided into zones, and locations in each grid are identified according to X and Y coordinates, often referred to as “offsets,” that provide values representing a distance, e.g., in feet, from a designated point of origin, the coordinates generally referred to as Easting and Northing, respectively. Considerable amounts of useful map data exists in Cartesian formats. Unfortunately, present mechanisms for projecting Cartesian mapping data into a geodetic system are lacking.